EXPLANATION OF PLATE III. 



Figs. 1-4. Poljjonax mortuaiius, ono-balf natural size. 



Fig. 1. Fragment of femur from side : a, same from below ; h, from above. 



2. Fragment of ?iscbium from side; a, narrower extremity; h, stouter extremity. 



3. Broken fragment of the other I ischium, edge view, showing internal cavity. 



4. Inside view of part of fibula: a, superior end view of the same. 

 Figs. 5-6. Bones of lliulronaurvs t occidcutaJis, from Colorado. 



Fig. 5. Fonith sacral vertebra from the tide, one-half natural size : a, same from below ; b, from front. 

 C. Fragment of head of tibia seen from above, four-tenths natural size. 



